Article

Recent studies have suggested the biomechanical subtasks of walking can be
produced by a reduced set of co-excited muscles or modules. Individuals
post-stroke often exhibit poor inter-muscular coordination characterized by poor
timing and merging of modules that are normally independent in healthy
individuals. However, whether locomotor therapy can influence module composition
and timing and whether these improvements lead to improved walking performance is
unclear. The goal of this study was to examine the influence of a locomotor
rehabilitation therapy on module composition and timing and post-stroke
hemiparetic walking performance. Twenty-seven post-stroke hemiparetic subjects
participated in a 12-week locomotor intervention incorporating treadmill training
with body weight support and manual trainers accompanied by training overground
walking. Electromyography (EMG), kinematic and ground reaction force data were
collected from subjects both pre- and post-therapy and from 19 age-matched
healthy controls walking on an instrumented treadmill at their self-selected
speed. Non-negative matrix factorization was used to identify the module
composition and timing from the EMG data. Module timing and composition, and
various measures of walking performance were compared pre- and post-therapy. In
subjects with four modules pre- and post-therapy, locomotor training resulted in
improved timing of the ankle plantarflexor module and a more extended paretic leg
angle that allowed the subjects to walk faster and with more symmetrical
propulsion. In addition, subjects with three modules pre-therapy increased their
number of modules and improved walking performance post-therapy. Thus, locomotor
training has the potential to influence module composition and timing, which can
lead to improvements walking performance.
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Langue : ANGLAIS